Spirals Are the Most Satisfying Way to Visualize Music
The Spiral Music visualizer, created by mechatronicsguy, provides a novel way to see music.
Music visualizers have a storied history that started long before those trippy WinAmp animations you used to love. Visualization has a practical purpose, such as aiding you in adjusting your stereo's equalizer. That standard visualizer breaks an audio signal up into several frequency ranges, so you can see each range's level with a quick glance. But it is possible to derive more information from the right kind of visualizer, including this Spiral Music visualizer created by mechatronicsguy.
This visualizer consists of 12 columns of LEDs arrayed radially, like spokes on a wheel. Each column contains six individual RGB LEDs, yielding 72 LEDs in total. A Teensy 3.6 board controls the LEDs based on MIDI signals coming from a connected computer and those correspond to the notes in either a MIDI file or played by a MIDI instrument. The LEDs sit on a wood board engraved with a spiral pattern and note labels, from C to C sharp, increasing in frequency through six octaves.
When a note plays, the LED at the corresponding note and octave will light up in a specific color assigned to the particular instrument. This lets you see an entire orchestra's music in a single visualizer, which makes it easy to identify chords formed by multiple instruments working in concert. You can also see transpositions and melodic inversion. Each LED has a decay timer, which creates a pseudo histogram that makes the key signature obvious. If you don't want to build the hardware, mechatronicsguy even wrote a version of the Spiral Music visualizer that works entirely in software.